What's the best way to write a character that's a different race than you?

Hey guys, I'm having a bit of trouble. I'm trying to get more diverse characters into my book, but I'm worried I'll offend people. I'm a white woman, and I'm trying to write a black man, but I keep feeling like I'm just reusing stereotypes and not getting it right. What can I do? I really want to get this character right.